This Program Project will be administered at the level of the University of Pennsylvania by the Office of Research Administration under the direction of Ms. Pamela Caudill. The Program includes a consortium arrangement with the Wistar Institute, which is a corporate entity separate from the University of Pennsylvania. Similar consortium arrangements presently exist between the two institutions and the financial and administrative officers of each are experienced in the efficient management of such arrangements. The participants in this Program Project are members of the faculty of the Medical School of the University of Pennsylvania. Thus, they have access to all of the resources of the institution.